The Web has transformed our lives by allowing us to transcend temporal, geographical and cultural borders. It is a fact that we get exposed daily to a seemingly unbound amount of diversity and, therefore, of opportunities; think for instance of the emergence of global digital platforms. At the same time, the Web often does not allow for prolonged interactions, thus amplifying the negative effects of diversity, in particular when it is unknown and unexpected; think for instance of the emergence of online fake news, bias and unethical behavior. In this talk we distinguish between two types of diversity, that we call inessential and essential diversity. We start from an analysis of inessential diversity, by far the one mostly studied so far, trying to put the current work on various related issues e.g., bias, transparency, fairness, under a new perspective. The second part of the talk will concentrate on essential diversity describing the first results of a large project whose main goal is to exploit diversity towards the empowerment of new types of online social relations.